A convenient and reliable locking assembly for doors is a critical and important part of any security system. In commercial settings, property must be secured to prevent theft and vandalism. In residential settings, a convenient and reliable locking assembly may even be more important where the safety of the inhabitants is also at stake.
Traditionally, mechanically operated locking assemblies are used in which the operator inserts a key into the locking device and then rotates the key to retract or extend a bolting mechanism. While this mechanical solution is reliable, there are many inconveniences associated with using a mechanical key system. For example, for a person in a dark area, it is difficult to find the key, orient the key, and insert it into the lock. Also, for a person occupied with carrying items, it is difficult to manage the items and also manipulate a key. These are only a few of the many limitations and inconveniences associated with a mechanically operated locking system.
Electrically operated locking assemblies have been proposed to address the limitations of purely mechanical locks. For example, U.S. Pat. Nos. 3,733,861, 4,148,092 and 5,487,289, issued to Lester, Martin and Otto, Ill., et al., respectively, disclose electrically activated locks. However, these locks provide an electrically operated passive means for restraining manual operation of the bolt mechanism. These systems do not have an active means for extending and retracting the bolt mechanism directly. Further, some of these systems do not allow concurrent manual and electric operation.
Recently the automobile industry has adopted remote controlled devices to actuate automobile door locks. The convenience of these remote control capabilities is tremendous in comparison with mechanically operated locks and has been well accepted by consumers. However, the use of remote controlled locking systems for doors outside of the automobile industry has been limited due to no reliable and economical actuating assembly which can be used with doors and dead-bolt assemblies such as those found in residences. In particular, there is no actuating assembly which can be adapted to utilize conventional dead-bolt assemblies and also retain the ability to use the conventional key method of operating a dead-bolt assembly. Further, there is no actuating assembly that can be retrofit to an existing dead-bolt assembly.
Therefore, a need exists for an electrically operated actuator assembly for automation of the locking and unlocking of dead-bolt assemblies, and in particular, a need exists for an electrically operated actuator assembly that can preserve the conventional key method of operation and also be retrofit to an existing dead-bolt assembly.